by David Coppedge

When does humor in a scientific journal cross the line of scientific objectivity? You be the judge. Science magazine, in its “Random Samples” news featurette, said this in the Jan. 18 issue:1

Over the past 100 million years or so, bats have evolved many features that distinguish them from their mammalian cousins. One is long, bony digits to support their wings.  Now, by manipulating one small DNA sequence, Richard Behringer of the University of Texas M. D. Anderson Cancer Center in Houston and colleagues have nudged mice a tiny step along the evolutionary path to bat-hood.

The researchers looked at the expression of a homeobox gene, prx1, a key to the development of limbs in all mammals, and found that bats expressed the gene differently from mice in embryonic limbs. So, in mice they removed a chunk of DNA known to control prx1 expression and replaced it with the same piece from bats. The forelimbs of the resulting mice were 6% longer than those of normal baby mice. Although small, that increase is “important,” says developmental biologist Clifford Tabin of Harvard Medical School in Boston.

Similar studies have been done with flies and worms, but this is the first to show how a specific change in control of gene expression — and not an actual gene — can produce a gross morphological change in a mammal, says Behringer, whose study was published this week in Genes & Development. “If you play this through with lots and lots of genes, maybe ultimately we could make that mouse fly out of the cage.”…

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